Riser Card Local EMI Shield for a Computer Chassis

1. An auxiliary shield and riser card assembly, configured to be used within a computer enclosure containing a system board, the computer enclosure defining a source compartment and an unshielded compartment therein, comprising: a riser card having a signal layer and a ground layer, a connector adjacent to an edge of the riser card, at least one cable connection socket on the riser card a first distance away from the connector, and a plurality of traces on the signal layer of the riser card running between the at least one cable connection socket and the connector, wherein the riser card is configured to be positioned between the source compartment and the unshielded compartment, and wherein the riser card is configured to be substantially orthogonal to the system board; a sheet of a conductive material positioned to cover at least a substantial portion of the plurality of traces; a plurality of non-conductive spacers disposed between and in contact with both of the sheet and the riser card; and at least one fastener connected to the sheet and attached to the ground layer of the riser card.

2. The auxiliary shield and riser card assembly of claim 1 , wherein the plurality of non-conductive spacers are made of a plastic material.

3. The auxiliary shield and riser card assembly of claim 1 , wherein the plurality of non-conductive spacers are attached to the sheet.

4. The auxiliary shield and riser card assembly of claim 1 , wherein holes are formed within the sheet, and wherein the plurality of non-conductive spacers are attached to the sheet by being pressed into the holes in the sheet.

5. The auxiliary shield and riser card assembly of claim 1 , wherein the sheet of conductive material is a metal sheet.

6. The auxiliary shield and riser card assembly of claim 1 , wherein the sheet of conductive material is a material selected from the group consisting of aluminum, aluminum alloy, copper, and copper alloy.

7. The auxiliary shield and riser card assembly of claim 1 , further comprising a channel-shaped lip along one edge of the sheet of conductive material.

8. The auxiliary shield and riser card assembly of claim 1 , wherein the sheet is spaced a distance of less than two centimeters from the riser card.

9. An auxiliary shield for a riser card, comprising: a sheet of a conductive material shaped to cover at least a portion of a signal layer of a riser card; a plurality of non-conductive spacers disposed on a surface of the sheet, each of the spacers protruding a distance from the surface and having distal ends disposed in a plane; at least one through hole in the sheet for attaching the sheet to the riser card using at least one fastener; a channel-shaped lip along one edge of the sheet of conductive material; and, an EMI gasket disposed along a top edge of the channel-shaped lip.

10. A shielded riser card assembly, comprising: a four-layer riser card having a connector adjacent to a lower edge thereof, at least one cable connection socket on the riser card a first distance away from the connector, and a plurality of traces on a surface of the riser card running between the at least one cable connection socket and the connector; a sheet of conductive material covering at least a substantial portion of the plurality of traces and spaced a second distance apart from the surface of the riser card; at least one fastener connected to the sheet and attached to the riser card, the at least one fastener connected to a ground layer of the riser card; and a plurality of non-conductive spacers disposed between and in contact with both of the sheet and the riser card.

11. The shielded riser card assembly of claim 10 , wherein the plurality of non-conductive spacers are made of a plastic material.

12. The shielded riser card assembly of claim 10 , wherein the plurality of non-conductive spacers are attached to the sheet.

13. The shielded riser card assembly of claim 10 , wherein the plurality of non-conductive spacers are attached to the sheet by being pressed into holes in the sheet.

14. The shielded riser card assembly of claim 10 , wherein the sheet of conductive material is a metal sheet.

15. The shielded riser card assembly of claim 10 , wherein the sheet of conductive material is a material selected from the group consisting of aluminum, aluminum alloy, copper, and copper alloy.

16. The shielded riser card assembly of claim 10 , further comprising a channel-shaped lip along one edge of the sheet of conductive material disposed over an upper edge of the riser card.

17. The shielded riser card assembly of claim 16 , further comprising an EMI gasket disposed along a top edge of the channel-shaped lip.

18. The shielded riser card assembly of claim 10 , wherein the second distance is less than two centimeters.

19. The shielded riser card assembly of claim 10 , wherein the connector is for connecting to a system board of an NLX system.

20. The shielded riser card assembly of claim 10 , wherein the at least one cable connection socket is on a second surface of the riser card opposite to the surface whereon the plurality of traces run.